Novel solutions to a bloody problem preventing full utilization of our marine resources -an interdisciplinary approach

Research Project, 2011 – 2014

Currently, a major part of the pelagic fish catches and fish filleting by-products (heads/frames) goes to oil and fodder meal production. On a world-wide basis, this equalizes ~7.5 million tones high quality proteins that could be directly processed into foods! Novel techniques for this are available today, but a real take-off is prevented by heavy pigmentation and poor oxidative stability of produced materials (fillets, minces, protein isolates/hydrolysates). The main components responsible for these quality impairments are the fish haemoglobins (Hb) and thus, the fish blood. Critical post mortem events leading to Hb-mediated oxidation/pigmentation are: (i) capillary burst, (ii) erythrocyte lysis caused e.g. by coagulation, mechanic rupture, temperature raises, osmotic pressure and erythrocyte membrane oxidation, and (iii) met-Hb formation/heme-loss. Using an interdisciplinary approach (food sci, hematology, fish phys), this project aims at developing novel strategies preventing Hb-contamination, and thus, facilitating for a more sustainable use of our marine resources. The specific aims are to: (i) perform a basic hematological characterization of blood from 3 important fish species (herring, cod, trout), (ii) develop an innovative incubation/rinsing solution for fish at various steps of the processing chain that prevents both coagulation and erythrocyte lysis, (iii) develop strategies for removal of liberated Hb/heme via extraction, precipitation and/or adsorption.